Cutaneous Squamous Cell Carcinoma Across the Pre-COVID-19, COVID-19 and Post-COVID-19 Eras: Epidemiology, Risk...

Background/Objectives: Cutaneous squamous cell carcinoma (cSCC) is the second most common non-melanoma skin cancer (NMSC) and represents the leading cause of NMSC-related deaths. Despite its growing global burden, comprehensive epidemiological and clinicopathological data from Easter Europe remains limited. This study aimed to evaluate the epidemiological, clinical, histopathological, and surgical characteristics of cSCC diagnosed before, during and after the COVID-19 pandemic. Methods: We conducted a retrospective, descriptive observational study including 332 lesions diagnosed between January 2017 and December 2025 at the Clinical Pathology Department of the Mureș Clinical County Hospital. Demographic, epidemiological, topographic, histopathologic, surgical, and volumetric parameters were analyzed. Tumours were stratified into low-, high-, and very-high-risk categories according to the National Comprehensive Cancer Network (NCCN) criteria. Results: The cohort demonstrated a significant male predominance (n = 193 vs. n = 139; p = 0.0355), with females presenting a higher median age (77 vs. 75; p = 0.0489). Lesions were predominantly located in the head and neck region (n = 216; p < 0.0001), which was significantly associated with very-high-risk tumours (p = 0.0051). Low-risk tumours accounted for 62.35% of cases, while high-risk and very-high-risk lesions comprised 19.88% and 17.77%, respectively (p < 0.0001). Ulcerations were strongly associated with very-high-risk tumours (p < 0.0001). Poor differentiation was more frequent outside the head and neck region (p < 0.0001) and varied significantly across the pandemic periods (p = 0.0349). Tumoral and excision volumes were higher in very-high-risk (p = 0.0070; p = 0.0004) and ulcerated tumours (p < 0.001), with a peak in volume during the COVID-19 period (p < 0.0001). A decrease through the years of diagnosis was observed in tumoral volumes (r = -0.2295; p < 0.0001) and patients showed a weak positive correlation with diagnosis year (r = +0.13; p = 0.019). Conclusions: The study provides an epidemiological and clinicopathological characterization of cSCC within one of the largest Romanian cohorts to date. Tumour aggressiveness was primarily driven by histopathological and topographical features rather than demographic factors. While the COVID-19 pandemic did not induce persistent changes in tumour risk profiles or surgical outcomes, it influenced diagnosis timing and tumour burden. These findings highlight the importance of incorporating temporal and emerging systemic factors, such as pandemics, and infectious events, into future epidemiological models to improve preparedness, early detection, future treatment schemes, and risk stratification in cSCC.